CVE-2026-5773
wrong reuse of SMB connection
Description
libcurl might in some circumstances reuse the wrong connection for SMB(S) transfers. libcurl features a pool of recent connections so that subsequent requests can reuse an existing connection to avoid overhead. When reusing a connection a range of criteria must be met. Due to a logical error in the code, a network transfer operation that was requested by an application could wrongfully reuse an existing SMB connection to the same server that was using a different 'share' than the new subsequent transfer should. This could in unlucky situations lead to the download of the wrong file or the upload of a file to the wrong place. When this happens, the same credentials are used and the server name is the same.
INFO
Published Date :
May 13, 2026, 1:01 p.m.
Last Modified :
May 13, 2026, 7:13 p.m.
Remotely Exploit :
Yes !
Source :
2499f714-1537-4658-8207-48ae4bb9eae9
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | HIGH | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | ||||
| CVSS 3.1 | HIGH | [email protected] |
Solution
- Update libcurl to the latest version.
- Review connection handling for SMB(S) transfers.
- Test connection reuse logic thoroughly.
Public PoC/Exploit Available at Github
CVE-2026-5773 has a 4 public
PoC/Exploit available at Github.
Go to the Public Exploits tab to see the list.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-5773.
| URL | Resource |
|---|---|
| https://curl.se/docs/CVE-2026-5773.html | Patch Vendor Advisory |
| https://curl.se/docs/CVE-2026-5773.json | Vendor Advisory |
| https://hackerone.com/reports/3650689 | Exploit Issue Tracking Third Party Advisory |
| http://www.openwall.com/lists/oss-security/2026/04/29/9 | Mailing List Patch Third Party Advisory |
| https://hackerone.com/reports/3650689 | Exploit Issue Tracking Third Party Advisory |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-5773 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-5773
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
RAD Security Image Scanner
Dockerfile Makefile Go
None
Dockerfile Makefile Shell Python
None
Ruby Shell Dockerfile Python Makefile
None
Shell Python
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-5773 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-5773 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
Initial Analysis by [email protected]
May. 13, 2026
Action Type Old Value New Value Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N Added CWE CWE-918 Added CPE Configuration OR *cpe:2.3:a:haxx:curl:*:*:*:*:*:*:*:* versions from (including) 7.40.0 up to (excluding) 8.20.0 Added Reference Type CVE: http://www.openwall.com/lists/oss-security/2026/04/29/9 Types: Mailing List, Patch, Third Party Advisory Added Reference Type curl: https://curl.se/docs/CVE-2026-5773.html Types: Patch, Vendor Advisory Added Reference Type curl: https://curl.se/docs/CVE-2026-5773.json Types: Vendor Advisory Added Reference Type CISA-ADP: https://hackerone.com/reports/3650689 Types: Exploit, Issue Tracking, Third Party Advisory Added Reference Type curl: https://hackerone.com/reports/3650689 Types: Exploit, Issue Tracking, Third Party Advisory -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
May. 13, 2026
Action Type Old Value New Value Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N Added Reference https://hackerone.com/reports/3650689 -
New CVE Received by 2499f714-1537-4658-8207-48ae4bb9eae9
May. 13, 2026
Action Type Old Value New Value Added Description libcurl might in some circumstances reuse the wrong connection for SMB(S) transfers. libcurl features a pool of recent connections so that subsequent requests can reuse an existing connection to avoid overhead. When reusing a connection a range of criteria must be met. Due to a logical error in the code, a network transfer operation that was requested by an application could wrongfully reuse an existing SMB connection to the same server that was using a different 'share' than the new subsequent transfer should. This could in unlucky situations lead to the download of the wrong file or the upload of a file to the wrong place. When this happens, the same credentials are used and the server name is the same. Added Reference https://curl.se/docs/CVE-2026-5773.html Added Reference https://curl.se/docs/CVE-2026-5773.json Added Reference https://hackerone.com/reports/3650689 -
CVE Modified by af854a3a-2127-422b-91ae-364da2661108
May. 13, 2026
Action Type Old Value New Value Added Reference http://www.openwall.com/lists/oss-security/2026/04/29/9